The downside: iPhone users have to access Google Latitude through MobileSafari, it won't show up in the App Store, it doesn't -- to our knowledge -- have access to Apple's push notification system, and in a brief tests, it seems to run less smoothly than it would as a native iPhone app.

The weird part: Latitude is precisely the kind of app that Apple helped enable by opening up the Google maps API for the 3.0 version of the iPhone software. And there are already several apps that Apple has approved for the App Store that do similar stuff, such as Apple-favorite Loopt, which happens to use Microsoft's (less elegant) map tiles.

So what's the deal? Perhaps Google wanted to do something that Apple wasn't into, like layer location-based/local ads on top of the iPhone's map tiles. Perhaps Apple is building their own similar service and didn't want Google's competing app anywhere near theirs. Perhaps Apps is building Latitude into the next version of its Maps app and thinks it'll do a better job than Google. Perhaps Apple really does think it's too complicated for its users to have two Google maps apps available for the iPhone -- one furnished as the default Maps app by Apple and one available for download from Google.

But it just seems strange that Apple isn't letting Google use their own maps for an iPhone app. Things do not seem to be getting cozier between Cupertino and Mountain View.

We worked closely with Apple to bring Latitude to the iPhone in a way Apple thought would be best for iPhone users. After we developed a Latitude application for the iPhone, Apple requested we release Latitude as a web application in order to avoid confusion with Maps on the iPhone, which uses Google to serve maps tiles.

And note that Google is eager to point out an annoying shortcoming on the iPhone; that it can't handle background processing:

Unfortunately, since there is no mechanism for applications to run in the background on iPhone (which applies to browser-based web apps as well), we're not able to provide continuous background location updates in the same way that we can for Latitude users on Android, Blackberry, Symbian and Window Mobile.